EXCEPTION SYSTEM (initial version - may change later)

This commit is contained in:
2025-12-24 13:56:41 +01:00
parent 3f789442c0
commit 09d9064372
11 changed files with 338 additions and 332 deletions

View File

@@ -7,177 +7,145 @@
use crate::{
consts::{Addr, Byte, DWord, HWord, Word},
core::Core,
instructions::{Instruction, InstructionResult},
exceptions::ExceptionType,
instructions::Instruction,
mem::PageNum,
};
// TODO: Support misaligned memory access
pub fn sd(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn sd(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_s());
if !addr.is_multiple_of(std::mem::size_of::<DWord>() as Addr) {
return InstructionResult::Exception(());
return Err(ExceptionType::StoreAmoAddressMisaligned);
}
let page = (addr / 4096) as PageNum;
let offset = (addr / 8 & ((4096 / 8 as Addr) - 1)) as u16;
let value = core.reg_read(instr.rs2());
match core.mem.write_dword(page, offset, value) {
Ok(_) => {
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.mem.write_dword(page, offset, value)?;
core.advance_pc();
Ok(())
}
pub fn ld(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn ld(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_i());
if !addr.is_multiple_of(std::mem::size_of::<DWord>() as Addr) {
return InstructionResult::Exception(());
return Err(ExceptionType::LoadAddressMisaligned);
}
let page = (addr / 4096) as PageNum;
let offset = (addr / 8 & ((4096 / 8 as Addr) - 1)) as u16;
match core.mem.read_dword(page, offset) {
Ok(x) => {
core.reg_write(instr.rd(), x);
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.reg_write(instr.rd(), core.mem.read_dword(page, offset)?);
core.advance_pc();
Ok(())
}
pub fn sw(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn sw(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_s());
if !addr.is_multiple_of(std::mem::size_of::<Word>() as Addr) {
return InstructionResult::Exception(());
return Err(ExceptionType::StoreAmoAddressMisaligned);
}
let page = (addr / 4096) as PageNum;
let offset = (addr / 4 & ((4096 / 4 as Addr) - 1)) as u16;
let value = core.reg_read(instr.rs2()) as Word;
match core.mem.write_word(page, offset, value) {
Ok(_) => {
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.mem.write_word(page, offset, value)?;
core.advance_pc();
Ok(())
}
pub fn lw(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn lw(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_i());
if !addr.is_multiple_of(std::mem::size_of::<Word>() as Addr) {
return InstructionResult::Exception(());
return Err(ExceptionType::LoadAddressMisaligned);
}
let page = (addr / 4096) as PageNum;
let offset = (addr / 4 & ((4096 / 4 as Addr) - 1)) as u16;
match core.mem.read_word(page, offset) {
Ok(x) => {
core.reg_write(instr.rd(), x as i32 as i64 as DWord);
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.reg_write(
instr.rd(),
core.mem.read_word(page, offset)? as i32 as i64 as DWord,
);
core.advance_pc();
Ok(())
}
pub fn sh(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn sh(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_s());
if !addr.is_multiple_of(std::mem::size_of::<HWord>() as Addr) {
return InstructionResult::Exception(());
return Err(ExceptionType::StoreAmoAddressMisaligned);
}
let page = (addr / 4096) as PageNum;
let offset = (addr / 2 & ((4096 / 2 as Addr) - 1)) as u16;
let value = core.reg_read(instr.rs2()) as HWord;
match core.mem.write_hword(page, offset, value) {
Ok(_) => {
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.mem.write_hword(page, offset, value)?;
core.advance_pc();
Ok(())
}
pub fn lh(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn lh(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_i());
if !addr.is_multiple_of(std::mem::size_of::<HWord>() as Addr) {
return InstructionResult::Exception(());
return Err(ExceptionType::LoadAddressMisaligned);
}
let page = (addr / 4096) as PageNum;
let offset = (addr / 2 & ((4096 / 2 as Addr) - 1)) as u16;
match core.mem.read_hword(page, offset) {
Ok(x) => {
core.reg_write(instr.rd(), x as i16 as i64 as DWord);
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.reg_write(
instr.rd(),
core.mem.read_hword(page, offset)? as i16 as i64 as DWord,
);
core.advance_pc();
Ok(())
}
pub fn sb(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn sb(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_s());
let page = (addr / 4096) as PageNum;
let offset = (addr & (4096 as Addr - 1)) as u16;
let value = core.reg_read(instr.rs2()) as Byte;
match core.mem.write_byte(page, offset, value) {
Ok(_) => {
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.mem.write_byte(page, offset, value)?;
core.advance_pc();
Ok(())
}
pub fn lb(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn lb(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_i());
let page = (addr / 4096) as PageNum;
let offset = (addr & (4096 as Addr - 1)) as u16;
match core.mem.read_byte(page, offset) {
Ok(x) => {
let x = x as i8 as i64 as DWord;
core.reg_write(instr.rd(), x);
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.reg_write(
instr.rd(),
core.mem.read_byte(page, offset)? as i8 as i64 as DWord,
);
core.advance_pc();
Ok(())
}
pub fn lbu(core: &mut Core, instr: Instruction) -> InstructionResult {
pub fn lbu(core: &mut Core, instr: Instruction) -> Result<(), ExceptionType> {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_i());
let page = (addr / 4096) as PageNum;
let offset = (addr & (4096 as Addr - 1)) as u16;
match core.mem.read_byte(page, offset) {
Ok(x) => {
let x = x as DWord;
core.reg_write(instr.rd(), x);
core.advance_pc();
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
core.reg_write(instr.rd(), core.mem.read_byte(page, offset)? as DWord);
core.advance_pc();
Ok(())
}